1. Technical Field
The present invention relates to maintenance apparatuses, liquid ejecting apparatuses, and maintenance methods.
2. Related Art
Ink jet printers have been widely known for some time as one type of liquid ejecting apparatus that ejects a liquid onto a medium. Such a printer records onto recording paper by ejecting ink (a liquid) from nozzles formed in a liquid ejecting head.
With such a printer, missing dots occur if bubbles enter into the nozzles within the recording head, making it difficult to eject the ink in a favorable manner; this in turn leads to a drop in the recording quality. Accordingly, a cleaning process that forcefully sucks and expels ink, bubbles, and so on from the nozzles of the recording head is executed.
Incidentally, in order to suck ink, bubbles, and so on from nozzles into which bubbles have entered, a suction force that is greater than the suction force sufficient to suck ink from properly-functioning nozzles that are ejecting ink in a favorable manner is necessary. Accordingly, there has been a problem in that when carrying out cleaning using suction, a large amount of ink is expelled from properly-functioning nozzles, resulting in the wasteful consumption of a large amount of ink. Accordingly, a maintenance apparatus that suppresses the consumption of ink during cleaning has been proposed, such as that disclosed in JP-A-2005-138313.
In other words, with the printer according to JP-A-2005-138313, suction cleaning is carried out in a state in which a porous film, through which a liquid can pass, is affixed to the nozzle formation surface of the recording head, the suction being carried out so as to allow air to pass and being carried out at a predetermined pressure. The amount of ink that is expelled during the suction cleaning is regulated by controlling the pressure applied to the recording head, which suppresses the amount of ink that is consumed.
Incidentally, with the maintenance apparatus according to JP-A-2005-138313, in the case where the diameter of the holes formed in the film affixed to the nozzle formation surface is greater than the diameter of the nozzles in the recording head, the pressure loss of the film becomes less than the pressure loss of the nozzles. Accordingly, the suction pressure applied to the nozzle formation surface of the recording head via the film is spread out equally across all of the nozzles, causing ink to be expelled even from the properly-functioning nozzles; this increases the amount of ink that is wastefully consumed.
On the other hand, in the case where the diameter of the holes formed in the film is smaller than the diameter of the nozzles, the pressure loss of the film will become greater than the pressure loss of the nozzles because the film is moistened by the sucked ink. Accordingly, there has been a problem in that the suction pressure applied to the nozzle formation surface via the film drops, which makes it difficult to expel bubbles from the nozzles into which the bubbles have entered.